The objectives of this study are to study the development of the vagina and cervix in aborted human fetuses and the effect of diethylstilbestrol (DES) on this developmental process. The morphogenetic sequence of formation of DES-induced vaginal adenosis will be documented in grafts of human fetal vaginal mucosa to nude mice and directly in NMRI mice. The role of the epithelial-stromal interaction in normal development of the human vagina, cervix, and uterus will be examined with tryptic separation and recombination experiments which will also be employed to elucidate the respective roles of epithelium and stroma in the development of vaginal adenosis in neonatal mice and human fetuses. To determine which tissue (epithelium or stroma) is the primary site of action of estrogens during urogenital development, the autoradiographic distribution of labelled natural and synthetic estrogens will be studied. Morphological analysis of estrogen-induced cervical lesions will be explored in NMRI mice, and the basis for subfertility in DES treated mice will be examined.